According to CNN, this particular individual has now been "taken into custody" (https://us.cnn.com/2020/07/24/politics/us-china-consulate-accuse-espionage-network/index.html), but no details are yet available as to how, exactly, this arrest was effected. I can't imagine that FBI agents were allowed onto PRC Consulate grounds, which means there must have been some kind of agreed-upon hand-over at the door, which in turn implies some kind of direct negotiation leading up to that. The tale is pretty tangled, in other words, and getting more so.